Said chand



(No Model.)

R. B. BOYNTON, D. L. CHANDLER 8u F. E. TBNNBY. POWER HAMMER.

No. 540,140. Patented May 28, 1895.

Y mm1 f\ l I IIIIIIII TINITED STAT-ES PATENT EEicEa ROYAL BULLARD BOYN TON, OE WEST TO WN SEND, AND DANIEL L. CHANDLER AND FRANK EVERETT TENN EY, OF

LER ASSIGNOR TO SAID BOYNTON.

AYER, MASSACHUSETTS; SAID CHAND- POWER-HAMMER.

SPECIFICATION forming part of Letters Patent No. 540,140, dated May 2S, 1895.

Application filed May 18, 1894:.

To @ZZ whom t may concern,.-

Be it known that we, ROYAL BULLARD BoYNToN, of West Townsend, and DANIEL L. CHANDLER and FRANK` EVERETT TENNEY, of

Ayer, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvementsin Power-Ham mers, of which the following is a specification.

This invention relates to that class of power Io ham mers in which the driving power is transmitted to the hammer-head through the medium of compressed air, a cylinder and piston being employed, and the hammer-head being carried by one of said parts while the power is t 5 applied to the other. The com pressed air, be-

sides acting as a cushion, constitutes an agent which can be so controlled as to vary the force of the stroke of the hammer-head.

The object of our invention is to simplify zo the means for controlling the compressed air, and to this end the invention consists in a power hammer which comprises a cylinder and piston, a hammer-head carried by one of' said parts, means for reciprocating the other 2 5 part, and a restricted passageaording communication from one side of the piston tothe other throughout the pistons stroke.

The invention also consists in other novel constructions and arrangements of parts here- 3o inafter described and claimed.

The accompanying drawings illustrate a construction by which the invention may be carried ont.

Figure l shows a side elevation of the ham- 3 5 mer. Fig. 2 shows a top plan View of the hammer. Fig. 3 shows a front elevation of the hammer. Fig. 4 shows a section on line 4: 4: of Fig. 3. Fig. 5 shows a bottom view of the piston. Fig. 6 shows a section on line 6 6 of 4o Fig. 3.

The same letters of reference indicate the same parts in all the figures.

In the drawings, the letter a designates the anvil, and b the supporting frame of the machine, which has a bifurcated portion b overhanging the anvil ,and its two branches having vertical slide-ways b2.

A cylinder c is provided with grooved ribs which engage said slide-ways, and said cyl- Seal No. 511,684. (No model.)

inder is extended at the lower end to form the 5o hammer-head c. The cylinder has an open port c2 centrally located in one side. A piston CZ fits the bore of the cylinder, and is carried on the end of a tubular rod d', which eX- tends through astufng-box in the upper end of the cylinder, and is fastened to a crosshead d2 fitting the ways b2. Apitman d3 connects said cross-head with a crank d4 on a driving-shaft e. Through these means the piston is reciprocated.

The piston is formed 'with two restricted passages f extending through it, and a valve f in the form of a winged plate, lits against the under side of the piston and controls said passages. Thesaid valve is carried on the lower end of a rod f2 which extends through the tubular piston-rod and beyond the same through a cross-piece 58 at the top of the frame b. A collar f 3 is supported in said cross-piece so as tol turn therein, and therod f2 has a groove f 4, which is engaged by a feather f 5 on the said collar.

An arm f6, projecting from the collar, is connected with one arm of a bell-crank lever g pivoted to the frame a and connected bya rod g with a treadle g2. It will be seen that by depressing the treadle g2 the valve f will be turned. The valve-rod f2 is prevented from moving longitudinally in the tubular pistonrod by a collar f7 fastened to the valve-rod and bearing against the upper end of the pist0n-rod.

In the operation of the hammer, the reciprocations of the piston impart the stro-ke to the hammer-head through the air compressed between the piston and the ends of the cylinder, the port c2 admitting air alternately on opposite sides of the piston to relieve the side opposite that where the compression takes place.A With the passages f in the piston closed by the valvef, the maximum force of the hammer blow is obtained. When a lighter blow is desired, the operator, by pressing on the treadle g2, turns the valve f and opens `the passages f more or less, and the air in the cylinder will not be compressed in the same degree as before. It will be observed. that this is a very' simp1e construction for accomplishing the desired end. By locating the port o2 centrally, as shown, a check-Valve is dispensed With, and the construction thereby further simplified.

It is. evident that variations may be made in the structure shown, Without departing from the invention. For example, the arrangement could be reversed by operatively connecting the cylinder with the reciprocating power and rigidly connecting the hammer with the piston, the hammer of course being then a separate part from the cylinder.

Having thus described our invention, what We claim as new, and desire to secure by Letters Patent, is-

l. A power-hammer comprising in its construction a cylinder and piston, a hammerhead carried by one of said parts, means for reciprocating the other part, and a restricted passage affording communication from one side of the piston to the other throughout the pistons stroke.

2. A power-hammer comprising in its construction a cylinder and piston, a hammerhead carried by one of said parts, means for reciprocating the other part, a restricted passage affording communication from one side of the piston to the other throughout the pistons stroke, and a valve controlling the area of said passage.

3. A power-hammer comprising in its construction a cylinder and piston, a hammerhead carried by one of said parts, means for reciprocating the other part, a restricted passage extending through the piston, and a valveadjustable to cover said passageor to leave it uncovered throughout the pistons stroke.

A. A power-hammer comprising in its construction'a cylinder having a centrally-located atmospheric port, a piston, a hammer-head carried by one of said parts, means for reciprocating the other part, and a restricted passageaffording communication from one side ofthe piston to the other throughout the pistons stroke.

In testimony whereof We-have signed. our

' names tothis specificatiomin the presence of tWov subscribing Witnesses, this 15th day of May,.A. D. 1894.

ROYAL BU LLARD BOYNTON. DANIEL L. CHANDLER. FRANK EVERETT TENNEY. Witnesses:

E. ALONZO BLOOD, HENRY B. BOYNTON.` 

